The deal values Cunningham at about $900 million to $1 billion including debt, said a person familiar with the transaction who declined to be identified because the figure is private. Fairfax is selling a stake for about $260 million, according to a statement Monday.

Greenwich-based Stone Point, run by former Goldman Sachs Group Inc. executives Stephen Friedman and Charles Davis, and Fairfax plan to remain investors, a separate statement showed.

Private-equity firms have bought and sold insurance-services firms this year as some look to cash out investments made during the buyout boom half a decade ago and others look to invest in an industry with steady cash flow and little need for capital expenditures. Cunningham, with about 7,000 employees, helps insurers and other companies determine losses and has operations in nations including Australia, Brazil, Germany, India, Japan and the U.S.

"CVC's diversified international coverage will be a tremendous asset to capitalize on as we broaden our global Presence," Cunningham Chief Executive Officer Philippe Bes said in a statement.

Fairfax, the Toronto-based insurer run by Prem Watsa, bought Cunningham Lindsey's predecessor in 1986 and took it public the next year, according to the adjuster's website. At the end of 2007, Fairfax bought out the publicly held shares and sold 51 percent to Stone Point. Fairfax had a 43 percent stake as of June 30, according to a company document.

Stone Point invests mostly in financial companies. Luxembourg-based CVC is the former European private-equity arm of Citigroup Inc.